/*
 * Copyright (c) 2006, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package com.sun.corba.se.impl.orbutil.threadpool;

import java.io.IOException ;

import java.security.PrivilegedAction;
import java.security.AccessController ;

import java.util.concurrent.atomic.AtomicInteger ;

import com.sun.corba.se.spi.orb.ORB ;

import com.sun.corba.se.spi.orbutil.threadpool.NoSuchThreadPoolException;
import com.sun.corba.se.spi.orbutil.threadpool.ThreadPool;
import com.sun.corba.se.spi.orbutil.threadpool.ThreadPoolManager;
import com.sun.corba.se.spi.orbutil.threadpool.ThreadPoolChooser;

import com.sun.corba.se.impl.orbutil.threadpool.ThreadPoolImpl;
import com.sun.corba.se.impl.orbutil.ORBConstants;

import com.sun.corba.se.impl.logging.ORBUtilSystemException ;
import com.sun.corba.se.impl.orbutil.ORBConstants ;
import com.sun.corba.se.spi.logging.CORBALogDomains ;


public class ThreadPoolManagerImpl implements ThreadPoolManager 
{ 
    private ThreadPool threadPool ;
    private ThreadGroup threadGroup ;

    private static final ORBUtilSystemException wrapper = 
	ORBUtilSystemException.get( CORBALogDomains.RPC_TRANSPORT ) ;

    public ThreadPoolManagerImpl() {
	threadGroup = getThreadGroup();
	threadPool = new ThreadPoolImpl( threadGroup,
	    ORBConstants.THREADPOOL_DEFAULT_NAME ) ;
    }

    private static AtomicInteger tgCount = new AtomicInteger() ;


    private ThreadGroup getThreadGroup() {
        ThreadGroup tg ;

        // See bugs 4916766 and 4936203
        // We intend to create new threads in a reliable thread group.
        // This avoids problems if the application/applet
        // creates a thread group, makes JavaIDL calls which create a new
        // connection and ReaderThread, and then destroys the thread
        // group. If our ReaderThreads were to be part of such destroyed thread
        // group then it might get killed and cause other invoking threads
        // sharing the same connection to get a non-restartable
        // CommunicationFailure. We'd like to avoid that.
        //
        // Our solution is to create all of our threads in the highest thread
        // group that we have access to, given our own security clearance.
        //
        try { 
            // try to get a thread group that's as high in the threadgroup  
            // parent-child hierarchy, as we can get to.
            // this will prevent an ORB thread created during applet-init from 
            // being killed when an applet dies.
            tg = AccessController.doPrivileged( 
                new PrivilegedAction<ThreadGroup>() { 
                    public ThreadGroup run() { 
                        ThreadGroup tg = Thread.currentThread().getThreadGroup() ;  
                        ThreadGroup ptg = tg ; 
                        try { 
                            while (ptg != null) { 
                                tg = ptg;  
                                ptg = tg.getParent(); 
                            } 
                        } catch (SecurityException se) { 
                            // Discontinue going higher on a security exception.
                        }
                        return new ThreadGroup(tg, "ORB ThreadGroup " + tgCount.getAndIncrement() ); 
                    } 
                }
            );
        } catch (SecurityException e) { 
            // something wrong, we go back to the original code 
            tg = Thread.currentThread().getThreadGroup(); 
        }

        return tg ;
    }
 
    public void close() {
        try {
            threadPool.close() ;
        } catch (IOException exc) {
            wrapper.threadPoolCloseError() ;
        }

        try {
            boolean isDestroyed = threadGroup.isDestroyed() ;
            int numThreads = threadGroup.activeCount() ;
            int numGroups = threadGroup.activeGroupCount() ;

            if (isDestroyed) {
                wrapper.threadGroupIsDestroyed( threadGroup ) ;
            } else {
                if (numThreads > 0)
                    wrapper.threadGroupHasActiveThreadsInClose( threadGroup, numThreads ) ;

                if (numGroups > 0)
                    wrapper.threadGroupHasSubGroupsInClose( threadGroup, numGroups ) ;

                threadGroup.destroy() ;
            }
        } catch (IllegalThreadStateException exc ) {
            wrapper.threadGroupDestroyFailed( exc, threadGroup ) ;
        }

        threadGroup = null ;
    }

    /** 
    * This method will return an instance of the threadpool given a threadpoolId, 
    * that can be used by any component in the app. server. 
    *
    * @throws NoSuchThreadPoolException thrown when invalid threadpoolId is passed
    * as a parameter
    */ 
    public ThreadPool getThreadPool(String threadpoolId) 
        throws NoSuchThreadPoolException {
            
        return threadPool;
    }

    /** 
    * This method will return an instance of the threadpool given a numeric threadpoolId. 
    * This method will be used by the ORB to support the functionality of 
    * dedicated threadpool for EJB beans 
    *
    * @throws NoSuchThreadPoolException thrown when invalidnumericIdForThreadpool is passed
    * as a parameter
    */ 
    public ThreadPool getThreadPool(int numericIdForThreadpool) 
        throws NoSuchThreadPoolException { 

        return threadPool;
    }

    /** 
    * This method is used to return the numeric id of the threadpool, given a String 
    * threadpoolId. This is used by the POA interceptors to add the numeric threadpool 
    * Id, as a tagged component in the IOR. This is used to provide the functionality of 
    * dedicated threadpool for EJB beans 
    */ 
    public int  getThreadPoolNumericId(String threadpoolId) { 
        return 0;
    }

    /** 
    * Return a String Id for a numericId of a threadpool managed by the threadpool 
    * manager 
    */ 
    public String getThreadPoolStringId(int numericIdForThreadpool) {
       return "";
    } 

    /** 
    * Returns the first instance of ThreadPool in the ThreadPoolManager 
    */ 
    public ThreadPool getDefaultThreadPool() {
        return threadPool;
    }

    /**
     * Return an instance of ThreadPoolChooser based on the componentId that was
     * passed as argument
     */
    public ThreadPoolChooser getThreadPoolChooser(String componentId) {
	//FIXME: This method is not used, but should be fixed once
	//nio select starts working and we start using ThreadPoolChooser
	return null;
    }
    /**
     * Return an instance of ThreadPoolChooser based on the componentIndex that was
     * passed as argument. This is added for improved performance so that the caller
     * does not have to pay the cost of computing hashcode for the componentId
     */
    public ThreadPoolChooser getThreadPoolChooser(int componentIndex) {
	//FIXME: This method is not used, but should be fixed once
	//nio select starts working and we start using ThreadPoolChooser
	return null;
    }

    /**
     * Sets a ThreadPoolChooser for a particular componentId in the ThreadPoolManager. This 
     * would enable any component to add a ThreadPoolChooser for their specific use
     */
    public void setThreadPoolChooser(String componentId, ThreadPoolChooser aThreadPoolChooser) {
	//FIXME: This method is not used, but should be fixed once
	//nio select starts working and we start using ThreadPoolChooser
    }

    /**
     * Gets the numeric index associated with the componentId specified for a 
     * ThreadPoolChooser. This method would help the component call the more
     * efficient implementation i.e. getThreadPoolChooser(int componentIndex)
     */
    public int getThreadPoolChooserNumericId(String componentId) {
	//FIXME: This method is not used, but should be fixed once
	//nio select starts working and we start using ThreadPoolChooser
	return 0;
    }

} 

// End of file.
